644316 has 12 divisors (see below), whose sum is σ = 1503432. Its totient is φ = 214768.

The previous prime is 644297. The next prime is 644327. The reversal of 644316 is 613446.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

644316 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26835 + ... + 26858.

It is an arithmetic number, because the mean of its divisors is an integer number (125286).

2⁶⁴⁴³¹⁶ is an apocalyptic number.

It is an amenable number.

644316 is an abundant number, since it is smaller than the sum of its proper divisors (859116).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644316 is a wasteful number, since it uses less digits than its factorization.

644316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53700 (or 53698 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

The square root of 644316 is about 802.6929674539. The cubic root of 644316 is about 86.3706733459.

The spelling of 644316 in words is "six hundred forty-four thousand, three hundred sixteen".